1. Field of the Invention
The present invention relates to a semiconductor device and more particularly, to a semiconductor device capable of forming a chopper circuit.
2. Description of the Background Art
Conventionally, there are circuits such as a step-down circuit, a step-up circuit, and a step-up/step-down circuit as DC-DC convertor circuits. Each of the step-down circuit, the step-up circuit, and the step-up/step-down circuit has a circuit configuration including a diode element and an IGBT (Insulated Gate Bipolar Transistor) serving as a switching element.
The step-down circuit and the step-up/step-down circuit include, for example, a configuration in which a cathode terminal of the diode element is connected to an emitter terminal of the IGBT (first type circuit: refer to FIG. 2). On the other hand, the step-up circuit includes, for example, a configuration in which an anode terminal of the diode element is connected to a collector terminal of the IGBT (second type circuit: refer to FIG. 3).
In addition, a chopper circuit having the first type circuit and a chopper circuit having the second type circuit have the well-known circuit configurations. For example, a step-up chopper circuit having the first type circuit is disclosed in Japanese Patent Application Laid-Open No. 11-113253 (1999). Meanwhile, a step-down chopper circuit and a step-up/step-down chopper circuit having the second type circuit are disclosed in Japanese Patent Application Laid-Open No. 09-322531 (1997).
However, according to the conventional configurations, it is necessary to prepare a semiconductor device having the first type circuit and a semiconductor device having the second type circuit, depending on intended usage. Therefore, since the two kinds of semiconductor devices need to be prepared, it is necessary to provide many circuit elements, which increases cost. In addition, on a user side, it is required to be able to easily select the step-down circuit (or step-up/step-down circuit) and the step-up circuit, in response to a request of the user.